Pub Date : 2026-01-14DOI: 10.1016/j.tws.2026.114530
Baidehi Das , Raffaele Barretta , Marko Čanađija
The present study investigates the dynamics of stress-driven nonlocal elastic beams exploiting the Physics-Informed Neural Network (PINN) approach. Specifically, a PINN is developed to compute the first eigenfunction and eigenvalue arising from the underlying sixth-order ordinary differential equation. The PINN is based on a feedforward neural network, with a loss function composed of terms from the differential equation, the normalization condition, and both classical boundary and constitutive boundary conditions. Relevant eigenvalues are treated as separate trainable variables. The results demonstrate that the proposed method is a powerful tool for addressing the complexity of the problem. The obtained results are compared with benchmark analytical solutions and show strong agreement.
{"title":"Physics-informed neural networks for nonlocal beam eigenvalue problems","authors":"Baidehi Das , Raffaele Barretta , Marko Čanađija","doi":"10.1016/j.tws.2026.114530","DOIUrl":"10.1016/j.tws.2026.114530","url":null,"abstract":"<div><div>The present study investigates the dynamics of stress-driven nonlocal elastic beams exploiting the Physics-Informed Neural Network (PINN) approach. Specifically, a PINN is developed to compute the first eigenfunction and eigenvalue arising from the underlying sixth-order ordinary differential equation. The PINN is based on a feedforward neural network, with a loss function composed of terms from the differential equation, the normalization condition, and both classical boundary and constitutive boundary conditions. Relevant eigenvalues are treated as separate trainable variables. The results demonstrate that the proposed method is a powerful tool for addressing the complexity of the problem. The obtained results are compared with benchmark analytical solutions and show strong agreement.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"222 ","pages":"Article 114530"},"PeriodicalIF":6.6,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145981102","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-14DOI: 10.1016/j.tws.2026.114519
Shuai Yang , Likun Zheng , Hanjun Gao , Yuhan Xin , Qiong Wu , Yan Zhang
Under the complex coupled effect of temperature and load fields, the internal stress state of carbon fiber reinforced polymers (CFRP) composites and its components undergo unpredictable changes, which greatly affects the accuracy and lifespan. In this study, the M55J-carbon fiber/cyanate ester (M55J-CF/CE) composites was used as the research object, which the bending strength and deflection experiment under high-low temperatures was performed, the strength decreases and the deflection value increases with the temperature rises was obtained, and provided parameters selection basis for the stress relaxation experiment research. Based on this, the stress relaxation experiment studies under high and low temperatures (-150°C ∼ +180°C) and initial loads (400 N, 800 N, and 1200 N) were carried out, and the high-temperature relaxation and low-temperature rebound relaxation variation law induced by the temperature-load-configuration was obtained. Furthermore, the constitutive parameters under the action of temperature and load were corrected based on the time-hardening model (THM), and the stress distribution prediction and evolution law research were carried out in combination with FEM. The research results show that temperature has the highest sensitivity to stress relaxation, and the relaxation trends caused by different loads are identical, the experiment maximum stress relaxation rate under the coupling effect of temperature and load is 58%, and the simulation prediction model error is <10%. Additionally, the cyclic angle laminate compared with single angle laminate shows an effect of ‘bias pressure mitigation leapfrog’ relaxation behavior, then the influence of layup angle, temperatures and initial loads to the stress relaxation mechanism were revealed.
{"title":"Stress relaxation behavior and prediction analysis under high-low temperature, initial load and angle-ply of M55J-CF/CE composites in spaceborne","authors":"Shuai Yang , Likun Zheng , Hanjun Gao , Yuhan Xin , Qiong Wu , Yan Zhang","doi":"10.1016/j.tws.2026.114519","DOIUrl":"10.1016/j.tws.2026.114519","url":null,"abstract":"<div><div>Under the complex coupled effect of temperature and load fields, the internal stress state of carbon fiber reinforced polymers (CFRP) composites and its components undergo unpredictable changes, which greatly affects the accuracy and lifespan. In this study, the M55J-carbon fiber/cyanate ester (M55J-CF/CE) composites was used as the research object, which the bending strength and deflection experiment under high-low temperatures was performed, the strength decreases and the deflection value increases with the temperature rises was obtained, and provided parameters selection basis for the stress relaxation experiment research. Based on this, the stress relaxation experiment studies under high and low temperatures (-150°C ∼ +180°C) and initial loads (400 N, 800 N, and 1200 N) were carried out, and the high-temperature relaxation and low-temperature rebound relaxation variation law induced by the temperature-load-configuration was obtained. Furthermore, the constitutive parameters under the action of temperature and load were corrected based on the time-hardening model (THM), and the stress distribution prediction and evolution law research were carried out in combination with FEM. The research results show that temperature has the highest sensitivity to stress relaxation, and the relaxation trends caused by different loads are identical, the experiment maximum stress relaxation rate under the coupling effect of temperature and load is 58%, and the simulation prediction model error is <10%. Additionally, the cyclic angle laminate compared with single angle laminate shows an effect of ‘bias pressure mitigation leapfrog’ relaxation behavior, then the influence of layup angle, temperatures and initial loads to the stress relaxation mechanism were revealed.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"222 ","pages":"Article 114519"},"PeriodicalIF":6.6,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145981181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-14DOI: 10.1016/j.tws.2026.114499
Ashish Kumar Singh , Atanu Sahu
Double-panel structures made of advanced composite materials are being used now-a-days in different aerospace applications. The present research work investigates the vibroacoustic energy transmission behaviour of functionally graded (FG) double-panel structures in hygrothermal environment by developing a numerical model based on a non-linear strain based finite element (FE) and a direct boundary element (BE) approaches. The structural panels are modelled using the FE method, wherein the first order shear deformation theory is adopted. The effect of hygrothermal environment is included in the FE model through Green–Lagrange non-linear strains in the elastic stress–strain relationship. The air-cavity in between the panels is modelled following the BE approach and are subsequently coupled to the FE model to ensure energy transfer between two domains. The present MATLAB based numerical model is verified by developing another FE model of the double-panel structure in COMSOL Multiphysics platform. A thorough investigation is done to evaluate individual and combined effects of temperature and moisture concentration, material gradation index, material properties of structural panels in the energy transmission behaviour of different FG double-panel structures. Results indicate that increased exposure of temperature and moisture concentration aid to a stronger mode coupling and thereby significantly enhances energy transmission through these structures. Moreover, less impact of FG material gradation on the energy transmission in hygrothermal environment is reported. These findings are valuable for developing effective vibration and noise control strategies, and will also serve as a benchmark for future research works in this area.
{"title":"A non-linear FE - direct BE based model for vibroacoustic energy transmission analysis through FG double-panel structures in hygrothermal environment","authors":"Ashish Kumar Singh , Atanu Sahu","doi":"10.1016/j.tws.2026.114499","DOIUrl":"10.1016/j.tws.2026.114499","url":null,"abstract":"<div><div>Double-panel structures made of advanced composite materials are being used now-a-days in different aerospace applications. The present research work investigates the vibroacoustic energy transmission behaviour of functionally graded (FG) double-panel structures in hygrothermal environment by developing a numerical model based on a non-linear strain based finite element (FE) and a direct boundary element (BE) approaches. The structural panels are modelled using the FE method, wherein the first order shear deformation theory is adopted. The effect of hygrothermal environment is included in the FE model through Green–Lagrange non-linear strains in the elastic stress–strain relationship. The air-cavity in between the panels is modelled following the BE approach and are subsequently coupled to the FE model to ensure energy transfer between two domains. The present MATLAB based numerical model is verified by developing another FE model of the double-panel structure in COMSOL Multiphysics platform. A thorough investigation is done to evaluate individual and combined effects of temperature and moisture concentration, material gradation index, material properties of structural panels in the energy transmission behaviour of different FG double-panel structures. Results indicate that increased exposure of temperature and moisture concentration aid to a stronger mode coupling and thereby significantly enhances energy transmission through these structures. Moreover, less impact of FG material gradation on the energy transmission in hygrothermal environment is reported. These findings are valuable for developing effective vibration and noise control strategies, and will also serve as a benchmark for future research works in this area.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"222 ","pages":"Article 114499"},"PeriodicalIF":6.6,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145981103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study investigates the tensile performance and low cycle fatigue (LCF) behavior of Triply Periodic Minimal Surface (TPMS) structures fabricated by Selective Laser Melting (SLM). Due to complex lattice geometry and inherent poor thermal stability of the SLM process, surface roughness of TPMS structures is increased. Micro-CT analysis reveals defects, such as pores and gas voids, within TPMS structures, less common in traditional plate samples. The defect porosity in TPMS structures is 325 times greater than in plate specimens. Although increasing pore spacing to 0.25 mm improves tensile performance and fatigue life, tensile strength of TPMS structures remains lower than Inconel 718 plate samples due to lower relative density and higher defect sensitivity. Both finite element analysis and experimental results confirm significant stress concentrations in TPMS structures, particularly around defects serving as potential crack initiation sites. In contrast, plate samples exhibit more uniform stress distribution and superior mechanical performance. EBSD analysis shows grains in plate samples are primarily uniformly distributed equiaxed fine grains, while TPMS structures contain larger grains in the central region, with fine grains concentrated at the edges. Moreover, dislocation accumulation occurred at TPMS thin-wall edges, and recrystallized grains increased significantly. High dislocation density becomes a weak point under long-term fatigue, leading to crack formation. Additionally, distinct subgrains observed after fatigue deformation indicate original equiaxed grains fragmented, exacerbating deformation. This caused coarse-grained regions to undergo substantial plastic deformation, generating numerous voids. These microstructural differences likely significantly influence the mechanical performance of TPMS structures.
{"title":"Effects of manufacturing defects and microstructure on the tensile and low cycle fatigue behavior of selective laser melting IN718 TPMS structures","authors":"Houjun Qin , Hui Hou , Changyou Xu , Jianan Song , Bensi Dong , Jia Huang","doi":"10.1016/j.tws.2026.114528","DOIUrl":"10.1016/j.tws.2026.114528","url":null,"abstract":"<div><div>This study investigates the tensile performance and low cycle fatigue (LCF) behavior of Triply Periodic Minimal Surface (TPMS) structures fabricated by Selective Laser Melting (SLM). Due to complex lattice geometry and inherent poor thermal stability of the SLM process, surface roughness of TPMS structures is increased. Micro-CT analysis reveals defects, such as pores and gas voids, within TPMS structures, less common in traditional plate samples. The defect porosity in TPMS structures is 325 times greater than in plate specimens. Although increasing pore spacing to 0.25 mm improves tensile performance and fatigue life, tensile strength of TPMS structures remains lower than Inconel 718 plate samples due to lower relative density and higher defect sensitivity. Both finite element analysis and experimental results confirm significant stress concentrations in TPMS structures, particularly around defects serving as potential crack initiation sites. In contrast, plate samples exhibit more uniform stress distribution and superior mechanical performance. EBSD analysis shows grains in plate samples are primarily uniformly distributed equiaxed fine grains, while TPMS structures contain larger grains in the central region, with fine grains concentrated at the edges. Moreover, dislocation accumulation occurred at TPMS thin-wall edges, and recrystallized grains increased significantly. High dislocation density becomes a weak point under long-term fatigue, leading to crack formation. Additionally, distinct subgrains observed after fatigue deformation indicate original equiaxed grains fragmented, exacerbating deformation. This caused coarse-grained regions to undergo substantial plastic deformation, generating numerous voids. These microstructural differences likely significantly influence the mechanical performance of TPMS structures.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"222 ","pages":"Article 114528"},"PeriodicalIF":6.6,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145981179","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-12DOI: 10.1016/j.tws.2026.114526
Changhai Chen , Siyuan Zhou , Yongqing Li
The protective performance of polyurea coated metal plates with various structural configurations under the combined action of air blast and fragments remains insufficiently understood. Additionally, there is a lack of relevant theoretical design methods. These aspects currently impede the widespread application of polyurea materials in the field of protective engineering. In this work, the protective performance of polyurea coated steel (PCS) plates under the combined action of air blast and fragments was compared through experiments and numerical simulations. The damage morphologies and energy absorption characteristics of PCS plates were analyzed, and compared with those of bare steel counterparts and ceramic-steel composite plates of the same total areal densities. The damage mechanisms of polyurea layers were microscopically analyzed. The effects of spraying position of polyurea, thickness allocation, and interface strength on the protective performance of PCS plates were elucidated. A theoretical design method was developed for steel-polyurea composite plates under the combined action of air blast and fragments from the perspective of safety. The results show that PCS plates with polyurea sprayed on the back face of steel layers have better protective performance than those with polyurea sprayed on the front face of steel layers. This is mainly because the rear polyurea layer (RPL) can sufficiently use its hyper-elasticity to enhance the energy absorption capacity of the front steel layer (FSL). PCS plates with suitable thickness allocation between FSL and RPL have superior protective performance compared to bare steel counterparts and ceramic-steel composite plates of the same total areal densities. The thicker FSL, the better protective performance of PCS plate under the same total areal density; this is because FSL is the main energy absorption component in the PCS plate. The proposed theoretical design method is reasonable and accurate, as well as conservative from the safety perspective.
{"title":"A comparative study on protective performance of polyurea-steel composite plates subjected to combined action of air blast and fragments","authors":"Changhai Chen , Siyuan Zhou , Yongqing Li","doi":"10.1016/j.tws.2026.114526","DOIUrl":"10.1016/j.tws.2026.114526","url":null,"abstract":"<div><div>The protective performance of polyurea coated metal plates with various structural configurations under the combined action of air blast and fragments remains insufficiently understood. Additionally, there is a lack of relevant theoretical design methods. These aspects currently impede the widespread application of polyurea materials in the field of protective engineering. In this work, the protective performance of polyurea coated steel (PCS) plates under the combined action of air blast and fragments was compared through experiments and numerical simulations. The damage morphologies and energy absorption characteristics of PCS plates were analyzed, and compared with those of bare steel counterparts and ceramic-steel composite plates of the same total areal densities. The damage mechanisms of polyurea layers were microscopically analyzed. The effects of spraying position of polyurea, thickness allocation, and interface strength on the protective performance of PCS plates were elucidated. A theoretical design method was developed for steel-polyurea composite plates under the combined action of air blast and fragments from the perspective of safety. The results show that PCS plates with polyurea sprayed on the back face of steel layers have better protective performance than those with polyurea sprayed on the front face of steel layers. This is mainly because the rear polyurea layer (RPL) can sufficiently use its hyper-elasticity to enhance the energy absorption capacity of the front steel layer (FSL). PCS plates with suitable thickness allocation between FSL and RPL have superior protective performance compared to bare steel counterparts and ceramic-steel composite plates of the same total areal densities. The thicker FSL, the better protective performance of PCS plate under the same total areal density; this is because FSL is the main energy absorption component in the PCS plate. The proposed theoretical design method is reasonable and accurate, as well as conservative from the safety perspective.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"222 ","pages":"Article 114526"},"PeriodicalIF":6.6,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145981186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Architected materials have attracted significant interest, primarily due to their unique capabilities in tailoring structural performance beyond conventional design limits. The current contribution investigates the flexural behavior of architected sandwich structures, featuring triply periodic minimal surface (TPMS) cores, and carbon fiber-reinforced polymer (CFRP) face sheets. Two core materials are investigated, namely polymeric and chopped carbon fiber (CF) reinforced 3D-printed cores, each fabricated with diverse TPMS topologies and core densities. Their flexural stiffness, strength, and energy absorption are assessed, identifying distinct mechanical performance differences. CF PPA cores allow for up to three times higher flexural modulus and strength compared to mere polymeric cores of the same density and architecture, approaching 2.5 GPa and 30 MPa, respectively. However, simple polymeric cores offer superior specific energy absorption through ductile, progressive crushing mechanisms, particularly prominent at higher core densities, aspects both experimentally and numerically characterized. Specific energy absorptions exceeding 600 J/kg are recorded for various polymeric core patterns at 30% core density, values twice those recorded for densities of 20%. The established core design and effective structural mechanics correlations provide benchmark results for the engineering of advanced, lightweight sandwich structures with exceptional flexural strength and energy absorption, leveraging cutting-edge additively manufactured metamaterial parts.
{"title":"Mechanics of carbon-fiber sandwich structures with additively-manufactured, polymeric and fiber-reinforced, TPMS metamaterial cores: Experiments and Modeling","authors":"Brijesh Phullel , Haris Mehraj , Agyapal Singh , Khaled Shahin , Nikolaos Karathanasopoulos","doi":"10.1016/j.tws.2026.114480","DOIUrl":"10.1016/j.tws.2026.114480","url":null,"abstract":"<div><div>Architected materials have attracted significant interest, primarily due to their unique capabilities in tailoring structural performance beyond conventional design limits. The current contribution investigates the flexural behavior of architected sandwich structures, featuring triply periodic minimal surface (TPMS) cores, and carbon fiber-reinforced polymer (CFRP) face sheets. Two core materials are investigated, namely polymeric and chopped carbon fiber (CF) reinforced 3D-printed cores, each fabricated with diverse TPMS topologies and core densities. Their flexural stiffness, strength, and energy absorption are assessed, identifying distinct mechanical performance differences. CF PPA cores allow for up to three times higher flexural modulus and strength compared to mere polymeric cores of the same density and architecture, approaching 2.5 GPa and 30 MPa, respectively. However, simple polymeric cores offer superior specific energy absorption through ductile, progressive crushing mechanisms, particularly prominent at higher core densities, aspects both experimentally and numerically characterized. Specific energy absorptions exceeding 600 J/kg are recorded for various polymeric core patterns at 30% core density, values twice those recorded for densities of 20%. The established core design and effective structural mechanics correlations provide benchmark results for the engineering of advanced, lightweight sandwich structures with exceptional flexural strength and energy absorption, leveraging cutting-edge additively manufactured metamaterial parts.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"222 ","pages":"Article 114480"},"PeriodicalIF":6.6,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145981104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-12DOI: 10.1016/j.tws.2026.114522
Lingchen Tian , Zehuan Li , Zailin Yang
An innovative fractional-order three-phase-lag (FTPL) thermoelastic framework is formulated for the thermal response of graphene-reinforced piezoelectric composites under sinusoidal heat shock, incorporating strain rate. This framework introduces both strain relaxation and memory-dependent effects into the graphene-reinforced piezoelectric composite material model for the first time, thereby filling the gap in existing theories that cannot accurately predict transient thermal shock processes in extreme environments. Based on this model, an analytical method using the Laplace transform and numerical inversion was employed to solve the thermoelastic dynamic response of graphene-reinforced composite piezoelectric layers. A comparative analysis evaluates the influence of graphene platelets distribution patterns (UD, FG-O, FG-X and FG-A types) on the structural response. In addition, parameter studies have shown that fractional-order parameters, total weight fraction of graphene platelets, strain relaxation factors and time factors are key parameters that affect thermomechanical behavior. This study not only provides a high-order accurate theoretical tool for predicting the coupling behavior of graphene-reinforced piezoelectric composites in transient thermal environments, but also provides a direct theoretical basis and parameter guidance for the material design and optimization of high-performance sensors and actuators.
{"title":"Rate-dependent thermoelastic dynamic response of graphene-reinforced composite piezoelectric structures using fractional-order three-phase-lag theory","authors":"Lingchen Tian , Zehuan Li , Zailin Yang","doi":"10.1016/j.tws.2026.114522","DOIUrl":"10.1016/j.tws.2026.114522","url":null,"abstract":"<div><div>An innovative fractional-order three-phase-lag (FTPL) thermoelastic framework is formulated for the thermal response of graphene-reinforced piezoelectric composites under sinusoidal heat shock, incorporating strain rate. This framework introduces both strain relaxation and memory-dependent effects into the graphene-reinforced piezoelectric composite material model for the first time, thereby filling the gap in existing theories that cannot accurately predict transient thermal shock processes in extreme environments. Based on this model, an analytical method using the Laplace transform and numerical inversion was employed to solve the thermoelastic dynamic response of graphene-reinforced composite piezoelectric layers. A comparative analysis evaluates the influence of graphene platelets distribution patterns (UD, FG-O, FG-X and FG-A types) on the structural response. In addition, parameter studies have shown that fractional-order parameters, total weight fraction of graphene platelets, strain relaxation factors and time factors are key parameters that affect thermomechanical behavior. This study not only provides a high-order accurate theoretical tool for predicting the coupling behavior of graphene-reinforced piezoelectric composites in transient thermal environments, but also provides a direct theoretical basis and parameter guidance for the material design and optimization of high-performance sensors and actuators.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"222 ","pages":"Article 114522"},"PeriodicalIF":6.6,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145981185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-12DOI: 10.1016/j.tws.2026.114496
Pedro Jacinto , Manuel Ritto-Corrêa , Rodrigo Gonçalves
This paper addresses the uniform torsion-shear problem of highly curved beams and the calculation of the associated warping function for a relatively large set of cross-sections. The equations required to obtain the warping function are derived and a 2D finite element discretization of the cross-section is employed to solve the problem. Two distinct types of warping functions are identified. Furthermore, it is shown that it is possible to define an analog to the center of twist in prismatic beams, herein designated as the “torsion-shear center”. Related cross-section geometric properties are derived, coinciding with the standard torsion and warping constants of the prismatic case in the limit of vanishing curvature. A broad set of cross-sections—primarily thin-walled, but also including two benchmark non-slender geometries—is analyzed to show the capabilities of the proposed method and to help advance the understanding of the torsion-warping behavior of curved beams.
{"title":"On the uniform torsion-shear-warping problem of highly curved beams","authors":"Pedro Jacinto , Manuel Ritto-Corrêa , Rodrigo Gonçalves","doi":"10.1016/j.tws.2026.114496","DOIUrl":"10.1016/j.tws.2026.114496","url":null,"abstract":"<div><div>This paper addresses the uniform torsion-shear problem of highly curved beams and the calculation of the associated warping function for a relatively large set of cross-sections. The equations required to obtain the warping function are derived and a 2D finite element discretization of the cross-section is employed to solve the problem. Two distinct types of warping functions are identified. Furthermore, it is shown that it is possible to define an analog to the center of twist in prismatic beams, herein designated as the “torsion-shear center”. Related cross-section geometric properties are derived, coinciding with the standard torsion and warping constants of the prismatic case in the limit of vanishing curvature. A broad set of cross-sections—primarily thin-walled, but also including two benchmark non-slender geometries—is analyzed to show the capabilities of the proposed method and to help advance the understanding of the torsion-warping behavior of curved beams.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"222 ","pages":"Article 114496"},"PeriodicalIF":6.6,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145981763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-11DOI: 10.1016/j.tws.2026.114521
Yu Bian , Feng Xiong , Ye Liu , Huanlong Ding , Yi Liao
To fully exploit the integrated structural and thermal advantages of precast concrete sandwich insulation panel, this paper proposes a new thin-walled ultra-high-performance concrete (UHPC) composite sandwich insulated wall panel (UCSP). The inner and outer wythes are each made of 20 mm thick UHPC, and anchorage-reinforced and connection-reinforced zones are arranged within the wythes. Experimental studies were conducted on the in-plane shear response and flexural response of UCSPs, comparing the effects of different inter-wythe connection schemes on panel performance. The results show that the flexural failure modes of UCSPs can be categorized into wythe failure and connection-system failure. When the peak shear load of the connection system increased by 29%, the degree of composite action improved by 15% in the elastic stage and 21% in the ultimate stage. For UCSPs with wythe through ribs, their flexural performance was close to that of a sandwich panel under the fully composite limit state. As the connection spacing was reduced by 50%, the flexural stiffness, peak load, and ductility of the UCSP increased by at least 31%, 25%, and 15%, respectively. Although UCSP reduced its self-weight by approximately 60% compared to conventional concrete sandwich panels, it could still withstand a uniformly distributed load of at least 5.4 kN/m² before cracking and exhibited deformation greater than 1/150 of its span at failure, demonstrating its excellent flexural performance. Finally, theoretical calculation models for the flexural bearing capacity and deformation of UCSP were established and verified against the test results. Overall, UCSP overcome the application difficulties of PCSPs in both nonstructural and structural roles.
{"title":"Flexural behaviour of a novel thin-walled UHPC composite sandwich insulated wall panel–Experimental and theoretical investigations","authors":"Yu Bian , Feng Xiong , Ye Liu , Huanlong Ding , Yi Liao","doi":"10.1016/j.tws.2026.114521","DOIUrl":"10.1016/j.tws.2026.114521","url":null,"abstract":"<div><div>To fully exploit the integrated structural and thermal advantages of precast concrete sandwich insulation panel, this paper proposes a new thin-walled ultra-high-performance concrete (UHPC) composite sandwich insulated wall panel (UCSP). The inner and outer wythes are each made of 20 mm thick UHPC, and anchorage-reinforced and connection-reinforced zones are arranged within the wythes. Experimental studies were conducted on the in-plane shear response and flexural response of UCSPs, comparing the effects of different inter-wythe connection schemes on panel performance. The results show that the flexural failure modes of UCSPs can be categorized into wythe failure and connection-system failure. When the peak shear load of the connection system increased by 29%, the degree of composite action improved by 15% in the elastic stage and 21% in the ultimate stage. For UCSPs with wythe through ribs, their flexural performance was close to that of a sandwich panel under the fully composite limit state. As the connection spacing was reduced by 50%, the flexural stiffness, peak load, and ductility of the UCSP increased by at least 31%, 25%, and 15%, respectively. Although UCSP reduced its self-weight by approximately 60% compared to conventional concrete sandwich panels, it could still withstand a uniformly distributed load of at least 5.4 kN/m² before cracking and exhibited deformation greater than 1/150 of its span at failure, demonstrating its excellent flexural performance. Finally, theoretical calculation models for the flexural bearing capacity and deformation of UCSP were established and verified against the test results. Overall, UCSP overcome the application difficulties of PCSPs in both nonstructural and structural roles.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"222 ","pages":"Article 114521"},"PeriodicalIF":6.6,"publicationDate":"2026-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145981180","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-11DOI: 10.1016/j.tws.2026.114520
Fatih Mehmet Özkal , Betül Aliş , Casim Yazici
Steel storage rack systems rely critically on semi-rigid beam-to-column connections (BCCs), which govern the global stability and seismic resilience of the structure. Despite their importance, a notable research gap persists regarding the residual performance and structural integrity of these connections following fire exposure and subsequent cooling. This study provides the first systematic connection-level experimental evaluation of how different cooling methods influence the post-fire performance of BCCs in steel storage rack systems. A comprehensive test program was conducted on specimens exposed to elevated temperatures ranging from 23°C to 800°C. Four distinct cooling protocols were applied, simulating practical extinguishing scenarios: air cooling (AC), fire-fighting foam cooling (FC), water spray cooling (SC), and water immersion cooling (WC). The residual moment-rotation behavior, moment resistance, rotational stiffness, rotational capacity, and ductility of the connections were systematically evaluated. The results demonstrated that all structural performance parameters decreased with rising exposure temperature, with accelerated degradation typically observed above 500–600°C. Gradual cooling methods (AC and FC) were the most effective, preserving a superior combination of strength and deformation capacity across the temperature range. Conversely, rapid water-based cooling (SC and WC) caused more substantial reductions in ultimate moment capacity. Although water immersion (WC) maintained numerically higher rotational stiffness at elevated temperatures, WC specimens exhibited a significant loss of ductility and rotational capacity compared to AC and FC, indicating a more brittle post-fire behavior. The findings emphasize that post-fire evaluation must account for the loss of ductility and the increased risk of brittle fracture associated with rapid quenching. In addition, cooling-dependent reduction factors and practical post-fire assessment recommendations are proposed, providing a direct engineering framework. This study provides crucial data for the structural assessment, repair decisions, and safe reuse determination of cold-formed steel rack components after a fire event.
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